## Documentation Index

Use Meters to submit usage data for the consumption of your products and services by end customers. This usage data then becomes the basis for setting up usage-based pricing for your products and services. Examples of usage data collected in Meters:

- Number of logins.
- Duration of session.
- Amount of data downloaded.

To collect usage data and ingest it into the platform, you can define two types of fields for Meters:

- `dataFields` Used to collect raw usage data measures - numeric quantitative data values or non-numeric point data values.
- `derivedFields` Used to derive usage data measures that are the result of applying a calculation to `dataFields`, `customFields`, or system `Timestamp` fields.

You can also:

- Create `customFields` for a Meter, which allows you to attach custom data to the Meter as name/value pairs.
- Create Global Meters, which are not tied to a specific Product and allow you to collect usage data that will form the basis of usage-based pricing across multiple Products.

**Use of PII:** The use of any of your end-customers’ Personally Identifiable Information (PII) in m3ter is restricted to a few fields on the **Account** entity. Please ensure that any fields you configure for Meters, such as Data Fields or Derived Fields, do not contain any end-customer PII data. See the [Introduction section](https://docs.m3ter.com/api) above for more details.

See also:

- [Reviewing Meter Options](https://docs.m3ter.com/guides/usage-data-meters/reviewing-meter-options).